The FDA has approved Orca Bio’s cell therapy Tregzi (Tregzi/Treg-based therapy) for patients undergoing matched-donor allogeneic HSCT after myeloablative conditioning, aiming to improve chronic graft-versus-host disease-free survival. Orca’s approach uses regulatory T cells (Tregs) to reduce the immune complications that have limited the long-term tolerability of allogeneic transplants. The approval follows results from Orca’s Precision-T phase III program that showed reduced risk of graft-versus-host disease versus standard transplantation approaches. Orca positions Tregzi as an alternative that preserves the curative potential of transplant while shifting the safety trade-off that clinicians and patients face when choosing HSCT for blood cancers. The company’s approval adds regulatory T cell therapy to a growing set of “living medicines” and sets a new bar for future allogeneic transplant platforms that target immune tolerance rather than only disease control.